We report a hitherto unknown occurrence of ancient Neoproterozoic evaporite deposits from an allochthonous terrane in the Pan-African Gariep belt in Namibia. Low contents of Rb, Cs, Ba, Zr, Hf, Th, and U, flat chondrite-normalised rare earth element (REE) patterns, Sr/Sr ratios as low as 0.7075, Na–Cl–Br systematics of fluid inclusion leachates, and high dB values for stratiform tourmalinites, ...

The Itapuranga alkali granite and Uruana quartz syenite are large K-rich EW-elongated intrusions, in the central part of the Neoproterozoic Brasília Belt, central Brazil. They are associated with Pireneus lineaments, which cut the regional NNW-SSE structures of the southern part of the belt. SHRIMP and conventional U-Pb data for the Itapuranga and Uruana intrusions indicate crystallization ages...

The Upper Mississippi Embayment (UME), where the seismically active New Madrid Seismic Zone resides, experienced two phases of subsidence commencing in the Late Precambrian and Cretaceous, respectively. To provide new constraints on models proposed for the mechanisms responsible for the subsidence, we computed and stacked P-to-S receiver functions recorded by 49 USArray and other seismic statio...

No. of 21 shale, limestone and gypsum samples belonging to the Palaeocene Sokoto Group and 19 sandstone, shale, lignite and gypsum samples from Maastrichtian age the Rima Group of the Sokoto Basin were collected from five traverses across hills and pits, and analyzed for major and trace elements using XRF and AAS analytical techniques. The SiO2/Al2O3 ratio of the Taloka Formation in the Rima Gr...

As the main constituent of large igneous provinces, the generation of continental flood basalts (CFB) that are characterized by huge eruption volume (>10(5) km(3)) within short time span (<1-3 Ma) is in principle caused by an abnormally high temperature, extended decompression, a certain amount of mafic source rocks (e.g., pyroxenite), or an elevated H2O content in the mantle source. These four...

[1] Adakitic melts from Papua New Guinea (PNG) show adakitic geochemical characteristics, yet their geodynamic context is unclear. Modern adakites are associated with hot-slab melting and/or remelting of orogenic mafic underplate at convergent margins. Rift-propagation over collision-modified lithosphere may explain the PNG adakite enigma, as PNG was influenced by rapid creation and subduction ...

[1] Nili Fossae is a region with fresh exposures of old material. OMEGA spectral data have revealed a strong diversity of minerals in the Nili Fossae region, including mafic minerals and phyllosilicates. Phyllosilicates are found to be primarily Fe-rich smectites (a type of clay minerals). These phyllosilicates are observed only on the Noachian crust, in four types of locations: Three are witho...

The Wooley Creek batholith and Slinkard pluton are adjacent plutons with identical U-Pb zircon ages of 161 +4/-2 Ma. The plutons dip toward each other, which suggests that they are connected in the subsurface. Geologic and thermochemical evidence shows that the Slinkard pluton is the structurally lowest part of the system and the Wooley Creek batholith the structurally highest, with a total str...

Mafic–ultramafics complexes are crucial for their tectonic implication, upper mantle condition, and hosting industrial minerals in a region. This study aims to highlight characterize the mafic–ultramafic rocks of Logar Ophiolite Complex using integration geospatial technology field data. The spatial distribution ophiolitic complex was examined this mineralogical indices (MI), band ratio (BR), s...